1. Field of the Invention
The invention relates to a system for displaying an image, the system being provided with selection means for selecting an area within the image, and reduction means for reducing a light intensity of the image.
The invention also relates to a method of displaying an image, the method comprising the steps of selecting an area within the image, and reducing the light intensity of the image.
2. Description of the Related Art
Such a system and method are known from European Patent Application No. EP-B-0 589 513, corresponding to U.S. Pat. No. 5,349,390, describing a number of light intensity-reducing functions protecting the processors and the display tube of television receivers from overload. The image quality is enhanced by these functions and the lifetime of the display tube is extended. A first light intensity-reducing function acts on larger areas, such as persons' faces, and is performed when the period during which the image signal in these areas exceeds a first threshold value, is longer than a given minimal period of time. This function reduces the light intensity of the entire image. The second intensity-reducing function is performed instantly when the maximally allowed amplitude of the image signal is exceeded. This second function reduces the light intensity locally. Both functions are only effective if the image signal exceeds given threshold values. However, practice has proved that there are parts of the image which may reduce the lifetime of a display tube, in spite of the fact that they do not exceed the threshold values.